The present invention relates to novel monoazoquinolone pigments, to a process for their preparation, and to their use as colourants, especially for coloring high molecular weight material.
Monoazoquinolone pigments are known. For example, U.S. Pat. No. 3,119,808 discloses monoazoquinolone pigments containing neither sulfonic acid groups nor carboxylic acid groups at the coupling component.
The ever greater demands made of the quality of colourations, for example the fastness properties, or of application-related properties, for example the migration behaviour or the oversprayability, have resulted in there still being a need for new pigments that exhibit improved properties, especially with regard to fastness properties.
Accordingly, the object underlying the present invention is to find novel, improved monoazoquinolone pigments, especially for producing surface coatings, printing inks and colour filters or for the colouring of plastics, which pigments possess the above-characterised qualities to a high degree. The novel pigments should yield colourations having a high purity of shade, high tinctorial strength, and good fastness to overspraying and migration. The resulting colourations should especially exhibit good fastness to heat, light and weathering.
It has been found that the stated object is largely achieved with the novel monoazoquinolone pigments defined hereinbelow.
Accordingly, the present invention relates to monoazoquinolone pigments which, in one of the tautomeric forms thereof, correspond to the formula 
wherein
Ar is a radical of the formula 
wherein
R1 is C1-C4alkyl,
R2 and R3 are each independently of the other hydrogen, halogen, C1-C4alkyl, carboxy, sulfo, cyano, C1-C4alkoxycarbonyl, C1-C4alkylcarbonyl, C1-C4alkanoylamino, benzoylamino that is unsubstituted or substituted in the phenyl ring by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy; carbamoyl, N-C1-C4alkylaminocarbonyl, N-arylaminocarbonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4-alkoxy; N,N-di-C1-C4alkylaminocarbonyl, C1-C4alkoxysulfonyl, C1-C4alkylsulfonyl, sulfamoyl, N-C1-C4alkylaminosulfonyl, N-arylaminosulfonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy; or N,N-di-C1-C4alkylaminosulfonyl,
wherein carboxy and sulfo are in the form of the free acid or in salt form,
R8 and R9 are each independently of the other hydrogen, halogen, C1-C4alkyl, C1-C4alkoxy, carboxy, sulfo, cyano, C1-C4alkoxycarbonyl, C1-C4alkylcarbonyl, C1-C4alkanoylamino, benzoylamino that is unsubstituted or substituted in the phenyl ring by halogen, nitro, C1-C4-alkyl or by C1-C4alkoxy; carbamoyl, N-C1-C4alkylaminocarbonyl, N-arylaminocarbonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4-alkoxy; N,N-di-C1-C4alkylaminocarbonyl, C1-C4alkoxysulfonyl, C1-C4alkylsulfonyl, sulfamoyl, N-C1-C4alkylaminosulfonyl, N-arylaminosulfonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy; or N,N-di-C1-C4alkylaminosulfonyl,
wherein carboxy and sulfo are in the form of the free acid or in salt form,
Ar1 is an aryl radical,
p is a number 0, 1 or 2, and
r is a number 0, 1 or 2, wherein (R8)r in formula (2f) denotes r identical or different radicals R8.
There come into consideration as C1-C4alkyl for R1, R2, R3, R8 and R9 each independently of the others, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl or isobutyl, preferably methyl or ethyl and especially methyl.
There come into consideration as C1-C4alkoxy for R8 and R9 each independently of the other, for example, methoxy, ethoxy, propoxy or butoxy.
There come into consideration as halogen for R2, R3, R8 and R9 each independently of the others, for example, fluorine, chlorine or bromine, preferably chlorine or bromine and especially chlorine.
There come into consideration as C1-C4alkanoylamino for R2, R3, R8 and R9 each independently of the others, for example, formylamino, acetylamino or propionylamino, especially acetylamino.
R2, R3, R8 and R9, each independently of the others, as benzoylamino are unsubstituted or substituted in the phenyl ring by halogen, for example chlorine or bromine, preferably chlorine; nitro; C1-C4alkyl, for example methyl, ethyl, n- or iso-propyl, n-, sec-, tert- or iso-butyl, preferably methyl or ethyl and especially methyl; or by C1-C4alkoxy, for example methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy or isobutoxy, preferably methoxy or ethoxy and especially methoxy.
There come into consideration as C1-C4alkoxycarbonyl for R2, R3, R8 and R9 each independently of the others, for example, methoxy-, ethoxy-, n-propoxy-, isopropoxy- or n-butoxy-carbonyl, preferably methoxy- or ethoxy-carbonyl and especially methoxycarbonyl.
There come into consideration as C1-C4alkylcarbonyl for R2, R3, R8 and R9 each independently of the others, for example, acetyl, propionyl, butyroyl or valeroyl, preferably acetyl or propionyl and especially acetyl.
There come into consideration as N-C1-C4alkylaminocarbonyl for R2, R3, R8 and R9 each independently of the others, for example, N-methyl-, N-ethyl-, N-propyl-, N-isopropyl-, N-butyl-, N-sec-butyl- or N-isobutyl-aminocarbonyl, preferably N-methyl- or N-ethyl-amino-carbonyl and especially N-methylaminocarbonyl.
There come into consideration as N-arylaminocarbonyl for R2, R3, R8 and R9 each independently of the others, for example, N-phenyl- or N-naphthyl-aminocarbonyl, preferably N-phenylaminocarbonyl. The mentioned radicals are unsubstituted or substituted in the aryl moiety by halogen, for example chlorine or bromine, preferably chlorine; nitro; C1-C4alkyl, for example methyl, ethyl, n- or iso-propyl, n-, sec-, tert- or iso-butyl, preferably methyl or ethyl and especially methyl; or by C1-C4alkoxy, for example methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy or isobutoxy, preferably methoxy or ethoxy and especially methoxy.
There come into consideration as N,N-di-C1-C4alkylaminocarbonyl for R2, R3, R8 and R9 each independently of the others, for example, N,N-di-methyl-, N,N-di-ethyl-, N-methyl-N-ethyl-, N,N-di-propyl-, N,N-di-isopropyl-, N,N-di-butyl-, N,N-di-sec-butyl-, N-methyl-N-sec-butyl- or N,N-di-isobutyl-aminocarbonyl, preferably N,N-di-methyl- or N,N-di-ethyl-aminocarbonyl and especially N,N-di-methylaminocarbonyl.
There come into consideration as C1-C4alkoxysulfonyl for R2, R3, R8 and R9 each independently of the others, for example, methoxy-, ethoxy-, n-propoxy-, isopropoxy- or n-butoxy-sulfonyl, preferably methoxy- or ethoxy-sulfonyl and especially methoxysulfonyl.
There come into consideration as C1-C4alkylsulfonyl for R2, R3, R8 and R9 each independently of the others, for example, methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, sec-butyl-, tert-butyl- or isobutyl-sulfonyl, preferably methyl- or ethyl-sulfonyl and especially methylsulfonyl.
There come into consideration as N-C1-C4alkylaminosulfonyl for R2, R3, R8 and R9 each independently of the others, for example, N-methyl-, N-ethyl-, N-propyl-, N-isopropyl-, N-butyl-, N-sec-butyl-, N-tert-butyl- or N-isobutyl-aminosulfonyl, preferably N-methyl- or N-ethyl-aminosulfonyl and especially N-methylaminosulfonyl.
There come into consideration as N-arylaminosulfonyl for R2, R3, R8 and R9 each independently of the others, for example, N-phenyl- or N-naphthyl-aminosulfonyl, preferably N-phenylaminosulfonyl. The mentioned radicals are unsubstituted or substituted in the aryl moiety by halogen, for example chlorine or bromine, preferably chlorine; nitro; C1-C4alkyl, for example methyl, ethyl, n- or iso-propyl, n-, sec-, tert- or iso-butyl, preferably methyl or ethyl and especially methyl; or by C1-C4alkoxy, for example methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy or isobutoxy, preferably methoxy or ethoxy and especially methoxy.
There come into consideration as N,N-di-C1-C4alkylaminosulfonyl for R2, R3, R8 and R9 each independently of the others, for example, N,N-di-methyl-, N,N-di-ethyl-, N-methyl-N-ethyl-, N,N-di-propyl-, N,N-di-isopropyl-, N,N-di-butyl-, N,N-di-sec-butyl-, N-methyl-N-sec-butyl- or N,N-di-isobutyl-aminosulfonyl, preferably N,N-di-methyl- or N,N-di-ethyl-aminosulfonyl and especially N,N-di-methylaminosulfonyl.
Ar1 as an aryl radical is preferably a phenyl or naphthyl radical, those radicals being unsubstituted or substituted by one or more substituents R8.
The carboxy and sulfo groups in the radicals of formulae (2a) and (2b) are bonded in the 2-, 3- or 4-position, preferably in the 4-position.
There come into consideration as carboxy and sulfo in the radicals of formulae (2a) and (2b) and for R2, R3, R8 and R9 both the free acid and their salts, for example the alkali metal, alkaline earth metal, transition metal or ammonium salts, salts of an organic amine, or mixtures thereof.
The present invention accordingly relates also to pigments of formula (1) wherein carboxy groups and sulfo groups are in salt form.
Examples of suitable alkali metal, alkaline earth metal or transition metal salts which may be mentioned are lithium, sodium, potassium, magnesium, calcium, strontium, barium, copper(I), copper(II), zinc(II), manganese(II) or aluminium(III) salts, preferably sodium, magnesium, calcium, strontium or barium salts.
Suitable salts of an organic amine or suitable ammonium salts contain, for example, cations of the formula 
wherein R4, R5, R6 and R7 are each independently of the others hydrogen, C1-C6alkyl, for example methyl, ethyl, n-propyl, n-butyl or n-pentyl, or phenyl or benzyl each of which is unsubstituted or substituted in the phenyl ring by C1-C4alkyl, for example methyl or ethyl, C1-C4alkoxy, for example methoxy or ethoxy, halogen, for example chlorine or bromine, nitro, amino, N-C1-C4alkylamino, for example N-methylamino or N-ethylamino, or by N,N-di-C1-C4alkylamino, for example N,N-di-methylamino or N,N-di-ethyl-amino. The following salts may be mentioned by way of example: the tetramethylammonium salt, the salt of mono-, di- or tri-methylamine or mono-, di- or tri-ethylamine, of benzylamine, of benzylamine monosubstituted in the phenyl ring by methyl, methoxy, chlorine or by nitro, of aniline, of N-methylaniline or of N,N-dimethylaniline.
The alkali metal, alkaline earth metal or transition metal salts of the pigments according to the invention are obtained, for example, by reaction of the pigments of formula (1) wherein the radical Ar contains carboxy and/or sulfo in the form of the free acid, with an alkali metal salt, alkaline earth metal salt or transition metal salt of an organic or inorganic acid, for example of acetic acid, carbonic acid, hydrochloric acid, nitric acid or sulfuric acid, by conventional processes.
The ammonium salts or the salts of an organic amine of the pigments according to the invention are obtained, for example, by reaction of the pigments of formula (1) according to the invention wherein the radical Ar contains carboxy and/or sulfo in the form of the free acid, with the corresponding amines by conventional processes.
Carboxy in the radical of formula (2a) and for R2 and R3 is preferably in the form of the free acid.
Sulfo in the radical of formula (2b) and for R2 and R3 is preferably in the form of the sodium, barium or calcium salt, especially the calcium salt.
R1 is preferably methyl or ethyl, especially methyl.
R2 is preferably hydrogen, halogen, C1-C4alkyl, cyano, C1-C4alkoxycarbonyl, C1-C4alkyl-carbonyl, C1-4alkanoylamino, benzoylamino that is unsubstituted or substituted in the phenyl ring by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy; carbamoyl, N-C1-C4alkylamino-carbonyl, N-arylaminocarbonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy; N,N-di-C1-C4alkylaminocarbonyl, C1-C4alkoxy-sulfonyl, C1-C4alkylsulfonyl, sulfamoyl, N-C1-C4alkylaminosulfonyl, N-arylaminosulfonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4-alkoxy; or N,N-di-C1-C4alkylaminosulfonyl.
R2 is particularly preferably hydrogen, halogen, C1-C4alkyl, C1-C4alkanoylamino, benzoyl-amino that is unsubstituted or substituted in the phenyl ring by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy, and especially hydrogen.
R3 is preferably hydrogen, halogen, C1-C4alkyl, carboxy, sulfo, cyano, C1-C4alkoxycarbonyl, C1-C4alkylcarbonyl, carbamoyl, N-C1-C4alkylaminocarbonyl, N-arylaminocarbonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4-alkoxy; N,N-di-C1-C4alkylaminocarbonyl, C1-C4alkoxysulfonyl, C1-C4alkylsulfonyl, sulfamoyl, N-C1-C4alkylaminosulfonyl, N-arylaminosulfonyl that is unsubstituted or substituted in the aryl moiety by halogen, nitro, C1-C4alkyl or by C1-C4alkoxy; or N,N-di-C1-C4alkylaminosulfonyl.
R3 is particularly preferably hydrogen, halogen, C1-C4alkyl, carboxy, sulfo, cyano, C1-C4-alkoxycarbonyl or carbamoyl.
R3 is most particularly preferably hydrogen, chlorine, methyl, carboxy, sulfo, methoxy-carbonyl or carbamoyl, preferably carboxy, sulfo or carbamoyl and especially carboxy.
In a preferred embodiment of the monoazoquinolone pigments according to the invention,
R1 is methyl and
R3 is hydrogen, chlorine, methyl, carboxy, sulfo or methoxycarbonyl, preferably carboxy, sulfo or carbamoyl and especially carboxy.
Ar is preferably a radical of formula (2a), (2b), (2c) or (2d).
Ar is particularly preferably a radical of formula (2a), (2b) or (2d), preferably of formula (2a) or (2d) and especially of formula (2d).
The present invention relates also to a process for the preparation of monoazoquinolone pigments of formula (1), wherein a compound of the formula 
is diazotised and coupled to a compound of the formula 
wherein Ar has the definitions and preferred meanings mentioned above.
The diazotisation of the compound of formula (3) is carried out, for example, using a nitrite, for example using an alkali metal nitrite, such as sodium nitrite, in a mineral-acid medium, for example in a hydrochloric acid medium, at temperatures of, for example, from xe2x88x925 to 40xc2x0 C. and preferably at from xe2x88x925 to 10xc2x0 C.
The coupling to the coupling component of formula (4) is carried out in a manner known per se at acid, neutral to weakly alkaline pH values, for example at a pH value of from 1 to 10, and at temperatures of, for example, from xe2x88x925 to 40xc2x0 C., preferably from 0 to 30xc2x0 C.
The process according to the invention is advantageously carried out by slowly adding a freshly prepared solution or suspension of the diazotised compound of formula (3) to a weakly acid to neutral solution or suspension of the acetoacetanilide coupling component of formula (4), the pH being maintained in the neutral range, for example at pH 4.5 to 8, by addition of an aqueous alkali hydroxide solution, for example a sodium hydroxide solution, subsequently stirring the resulting pigment suspension until the reaction is complete, and isolating the product by filtration.
The compound of formula (3) is known and can be obtained, for example, according to the process described in U.S. Pat. No. 3,119,808. The compounds of formula (4) are known or can be obtained by processes known per se.
The monoazoquinolone pigments of formula (1) according to the invention are suitable as colourants for colouring high molecular weight material.
The high molecular weight material can be organic or inorganic and may be a synthetic and/or natural material. It may be, for example, natural resins or drying oils, rubber or casein, or modified natural materials such as chlorinated rubber, oil-modified alkyd resins, viscose, cellulose ethers or esters, such as ethyl cellulose, cellulose acetate, propionate or butyrate, cellulose acetobutyrate as well as nitrocellulose, but especially totally synthetic organic polymers (thermosetting plastics and thermoplastics), as can be obtained by polymerisation, for example by polycondensation or polyaddition. The polymer class includes, for example, polyolefins, such as polyethylene, polypropylene, polyisobutylene, also substituted polyolefins, such as polymerisation products of monomers such as vinyl chloride, vinyl acetate, styrene, acrylonitrile, acrylic acid esters, methacrylic acid esters; fluoropolymers, for example polyfluoroethylene, polytrifluorochloroethylene or tetrafluoroethylene/hexafluoropropylene mixed polymers, as well as copolymers of the mentioned monomers, especially ABS (acrylonitrile/butadiene/styrene) or EVA (ethylene/vinyl acetate). From the group of the polyaddition and polycondensation resins it is possible to use, for example, condensation products of formaldehyde with phenols, the so-called phenoplasts, and condensation products of formaldehyde and urea or thiourea, and also melamine, the so-called amino-plasts, also the polyesters used as surface-coating resins, either saturated, such as alkyd resins, or unsaturated, such as maleic resins, also linear polyesters, polyamides, polyurethanes, polycarbonates, polyphenylene oxides or silicones, and silicone resins.
The mentioned high molecular weight compounds may be present individually or in mixtures, in the form of plastic compositions or melts, which may optionally be spun to form fibres.
They may also be present in the form of their monomers or in the polymerised state in dissolved form as film-forming agents or binders for surface coatings, paints or printing inks, such as boiled linseed oil, nitrocellulose, alkyd resins, melamine resins, urea-formaldehyde resins or acrylic resins.
Pigmenting of the high molecular weight organic materials with the monoazoquinolone pigments according to the invention is carried out, for example, by adding such a pigment, optionally in the form of a masterbatch, to the substrates using rolling mills, mixing or grinding apparatuses. The pigmented material is then generally brought into the desired final form by methods known per se, such as calendering, compression moulding, extrusion, spread-coating, casting or by injection moulding. It is often desirable, in order to produce non-rigid mouldings or to reduce their brittleness, to incorporate so-called plasticisers into the high molecular weight compounds before they are shaped. There may be used as plasticisers, for example, esters of phosphoric acid, phthalic acid or sebacic acid. The plasticisers may be incorporated in the process according to the invention before or after the incorporation of the pigment colourant into the polymers. It is also possible, in order to achieve different shades of colour, to add to the high molecular weight organic materials, in addition to the monoazoquinolone pigments of formula (1), also fillers or other constituents imparting colour, such as white, coloured or black pigments as well as special-effect pigments, in each case in the desired amount.
For the pigmenting of surface coatings and printing inks, the high molecular weight organic materials and the monoazoquinolone pigments of formula (1), optionally together with additives such as fillers, other pigments, for example TiO2, siccatives or plasticisers, are generally finely dispersed or dissolved in an organic and/or aqueous solvent or solvent mixture. The procedure may be such that the individual components are dispersed or dissolved separately or several are dispersed or dissolved together, and only then are all the components combined.
Based on the high molecular weight material to be pigmented, the monoazoquinolone pigments according to the invention can be used in an amount of from 0.01 to 30% by weight, preferably from 0.1 to 10% by weight.
Accordingly, the present invention relates also to the use of the monoazoquinolone pigments of formula (1) according to the invention in the colouring of high molecular weight material, especially organic high molecular weight material, which includes the use as a colourant for plastics in any form, for example in the form of fibres, surface coatings or printing inks.
The monoazoquinolone pigments of formula (1) according to the invention are especially suitable for the colouring, in the mass, of polyvinyl chloride and, especially, polyolefins, such as polyethylene and polypropylene, as well as of aqueous and/or solvent-based lacquers, for example automotive lacquers, also powder coatings, printing inks and paints.
The resulting colourants, for example in plastics, fibres, surface coatings or prints, are distinguished by a high purity of shade, high tinctorial strength, good fastness to over spraying and migration, and especially by good fastness to heat, light and weathering, for example in full-shade or reduction with white applications.
The monoazoquinolone pigments of formula (1) according to the invention are further distinguished by good dispersibility, good rheological behaviour and a high gloss of the colourants obtained therewith.
It is assumed that the advantageous properties of the pigments according to the invention are attributable to the specific choice of substituents and the substitution pattern at the phenyl radical Ar.
The monoazoquinolone pigments of formula (1) according to the invention are also suitable as colourants for the production of colour filters, especially for visible light in the range from 400 to 700 nm, for liquid crystal displays (LCD) or charge combined devices (CCD). The monoazoquinolone pigments of formula (1) can be used alone or in combination with suitable red, blue and/or green pigments.
The production of colour filters by the sequential application of a red, blue and green pigment to a suitable substrate, for example amorphous silicon, is described in GB-A 2 182 165. The colour filters can be coated, for example, using inks, especially printing inks, comprising the monoazoquinolone pigments according to the invention, or, for example, by mixing the monoazoquinolone pigments according to the invention with chemically, thermally or photolytically structurable high molecular weight material. The further production can be carried out, for example, analogously to EP-A 654 711 by application to a substrate, such as an LCD, subsequent photostructuring and development. A further document which describes the production of colour filters is U.S. Pat. No. 5,624,467.
The colour filters produced with the pigments according to the invention for liquid crystal displays (LCD) exhibit an improved transmission window between 500 and 600 nm in comparison with colour filters known hitherto, and they are therefore distinguished by high transmission of the green colour points. The colour filters produced with the pigments according to the invention have increased absorption at 400 nm in comparison with the colour filters known hitherto, which advantageously yields a more yellowish green.
The Examples which follow serve to illustrate the invention.